Effect of Regulated Deficit Irrigation on the Growth, Yield, and Irrigation Water Productivity of Processing Tomatoes under Drip Irrigation and Mulching

Abstract

The application of regulated deficit irrigation (RDI) strategies with high water-saving effects for processing tomatoes is an important current research trend. In this study, we aimed to reveal the patterns of growth, yield, and irrigation water productivity (WPI) in response to the water deficit in processing tomatoes under drip irrigation and plastic mulching in Xinjiang. To determine a more precise irrigation regime, various degrees of RDI treatments were applied to processing tomatoes in 2022 and 2023. A total of five water gradients were set up: RI (Regular Irrigation; 4500 m3/ha), W1 (4185 m3/ha), W2 (3870 m3/ha), W3 (3555 m3/ha), and W4 (3240 m3/ha). The results revealed that under RI, the yield and irrigation water productivity were 142 t/ha and 31.49 kg/m3, respectively. Compared with RI, W1 exhibited an increase in yield and irrigation water productivity of 12.13% and 22.39%, respectively; however, other treatments exhibited a decrease. The main reasons for the increase in yield under the W1 treatment were: the W1 treatment, improved photosynthetic performance, increased dry matter accumulation, and improved soil moisture conditions, thus promoting plant growth and development. In addition, in terms of water regulation at various fertility stages, moderate water deficiency at the seedling stage (S), flowering stage (F), and maturity stage (M) and rewatering at the fruit expansion stage (E) were more conducive to optimizing the yield structure. In conclusion, considering plant growth status, dry matter accumulation, yield, and WPI, we suggested that the W1 treatment is the optimal RDI mode most suitable for drip irrigation under mulching for processing tomatoes in Xinjiang. This study provided a theoretical and technical basis for the promotion of “water-saving and efficiency-enhancing” production of processing tomatoes.

Simulation of Daily Transpiration of Tomatoes Grown in Venlo-Type Greenhouse Substrates

“…Therefore, it is recommended to take a 70% matrix water-holding capacity as the lower limit of irrigation for high-yield and high-quality tomato production. However, due to the different sensitivities of tomatoes to water at the different growth stages [41], the impact of water stress on the tomato yield and quality during the various growth stages remains to be elucidated. Therefore, different water treatments need to be conducted at different growth stages to further investigate the effects of water stress on the yield and quality of tomatoes grown in a substrate.…”

Evaluation of Crop Water Stress Index (CWSI) for High Tunnel Greenhouse Tomatoes under Different Irrigation Levels

“…Except for 100% treatment, the WUE in the two seasons gradually decreased as ETc increased and reached a maximum value under 60% treatment. Xu et al [52] conducted an experiment for small-scale water saving with the conventional irrigation amount (4500 m 3 /ha) as the basis, decreasing by 7%, 14%, 21%, and 28% successively. Overall, it was reported that marketable yield and irrigation water productivity tended to increase and then decrease with decreasing irrigation levels.…”

Design and Optimization of Precision Fertilization Control System Based on Hybrid Optimized Fractional-Order PID Algorithm

“…The system operates in an 'irrigation-fertilization-irrigation' mode, with the first irrigation ensuring sufficient soil moisture and the second irrigation promoting the absorption and utilization of nutrients by plants. Irrigation and fertilization are achieved by opening and closing corresponding electromagnetic valves [13][14][15][16]. During independent irrigation, electromagnetic valves 1, 2, and 4 are closed, while 3 is open.…”